Method of regulating shot sizes



P 1951 l. M. OLSEN I 2,567,121

METHOD OF REGULATING SHOT SIZES F iled Mairch 8, 1946 [DAR M ULEEN 35% f QM Patented Sept. 4, 1951 UNITED STATES PATIENT OFFICE 2,567,121 METHOD'OF REGUIJATING SHOT SIZES Idar Olsen, Jackson, Mich.

Application March 8, 1946, Serial'No. 652,900

2 Claims. (Cl. 1847.3)

The present invention relates to improvements in methods for producing metallic shot and grit used for peening, cleaning, abrasion and similar purposes.

The object of the invention is to provide a method capable of producing shot of a more uniform size, making it possible to control to a considerable extent the size of the shot being formed, and reducing the percentages of extremely large and eittremely small sizes produced.

Peening shot now being used is generally of white cast iron made by breaking up a stream of molten iron by a blast of water, steam or other suitable material and rapidly cooling the resultant globules of molten iron. To break up the molten stream of metal asit flows from-the furnace, at the mouth of the metal runner, there have been numerous suggestions and attempts to improve the shape of the metal stream at the point at which it is broken up. It has notbeen found possible, however, to design a valve, jet, or orifice which would deliver the molten metal in a thin ribbon to the point at which the molten stream is subjected to the atomizing action of the water, steam or air jets. The high temperature of the molten metal and the inability of any material other than fireclayand refractory bricks capable of withstanding high temperatures has ;made the design of such devices cumbersome and has necessitated application of the atomizing jets at a point at'which the molten stream is far from being ribbon-like, with the result that the atomization of the molten stream by the jets of water, air and steam is not at all uniform nor is the resulting solidified globule of uniform size or shape. Moreover, the only control exercised in methods heretofore used has been confined to increasing or decreasing the pressure of the atomizing medium. 1

According to the present invention, more uniform results may be obtained in the manufacture of shot and the size may be controlled through the provision of a suitable heat-resisting surface located forward and below the metal runner and functioning to spread the stream of molten metal depth of the ribbon-like molten stream of metal and in this way controls to a considerable degree the size of-the dominant shot being produced.

lever 28.

Another object of the invention is to provide an improved method-for the manufacture of peening and cleaning shot and grit characterized by more uniform size.

Another object is to provide an improved method for controlling the shape of a molten stream of metal to bebroken up forming peening shot and rit.

A still further object of the invention is to provide an improved method for controlling the shape of a molten stream of metal in order to vary the size of the shot formed by the disintegration of the molten stream through the action of steam, air or water.

A still further object of the invention resides in a method for controlling the shape of. a molten stream of metal in the form of a refractory surface supported so as to regulate its angularity.

A further object is to provide a method of disintegrating a molten stream of metal which eliminates the need of .high volume or high pressure blowing media. I

' A still further object is to provide a method for producing shot of the type described, in which surges of metal from the cupola operation do not materially affect uniform size formation.

These and other objects and advantages residing in the method will be more fully appreciated from a consideration of the following specification and claims.

In the drawings,

Fig. I is a perspective view of a metal runner o a furnace with one form of suitable apparatus shown carrying out the principles of the present invention, and 1 Figs. II and III illustrate the manner in which the molten stream is spread.

The principles of the invention have been very simply illustrated in connection with the usual metal runner I 0 having a refractory liner l2 and connecting at its inner end with a cupola furnace in which the charge is melted down and then drawn off. vIn lieu of the usual nozzles for breaking up the stream of metal as it flows over the end l4, being located adjacent thereto, the

metal stream I5 is discharged upon a suitable refractory surface l8 supported in a frame 20 and mounted for oscillating movement upon-a shaft 22. A'suitable bearing 24 supports the shaft 22 for rotation with one end of the shaft 22 being provided with a lever 28; The shaft 22 has sufficient drag against rotation in the bearing 24 to hold the shaft 22 and the surface 18 in different angular adjustments under the regulation of the At the lower end of the surface l8 and directly adjacent thereto are a series of jets or nozzles 34 connecting with a manifold 36 which in turn is in communication through a flexible conductor 38 with a source of steam, air or Water depending upon the medium being employed for atomizing or breaking up of the thin ribbon of metal flowin over the end 40 of the surface l8. The manifold 36 is supported in the frame 20 so that the jets and nozzle 34 will maintain the samerelationship with reference to the end 40 of the surface [8 upon angular adjustment through rocking of, the shaft 22.

It will be noted from Fig. I that the surface I8 is substantially wider than metal runner l0. Also apparent from consideration of Fig. I is-the manner in which the stream [6 spreads out under the influence of gravity as it contacts with the surface l8.

By varying the angularity of the surface [8, the

:amount that the stream IE will spread out thereon may be regulated. This should be obvious. The more closely the surface l8 approaches the horizontal, the wider the stream IE will be spread upon the-surface l8, and the thinner will be the ribbon of molten metal pouring over the end 40.

As will be .readily appreciated, if the stream 16 is spread out too thin on the surface I8, it will slow down to too-great an extent, and cooling of the .molten metal will take .place along the outer edge, causing a sluggishness. Accordingly, the length of the surface 18 should not be too great nor should it .be adjusted too near to a horizontal position. In order to reduce the spreading action of the stream I6 on the surface l8 and to thicken up-the ribbon of molten metal passing over the end 40, it .is only necessary to increase the anmolten stream passing over the edge 40 the globules formed and quenched in the bath 44 will be more uniformly of one size than has been hereto- .fore possible with existing methods and apparatus. Should a similarly uniform but larger size shot be required, by increasing the angularity of the surface N3, the stream I6 is spread upon the surface 18 to a lesser extent providing a thick-er rod 52actuates the carriage 46 through a rod 54.

For raising and lowering the surface It relative to the runner ill, the track 48 may be adjustably supported in any suitable manner.

In Fig. II is illustrated the manner in which the stream is is spread on the surface l8 by the action of gravity and is thereafter contracted by surface tension. According to my improved method-the stream is subjected to the action of fluid pressure before any substantial contraction J takes place. Fig. III shows the manner in which the stream I6 is thinned out into a ribbon as it flows toward the edge of the surface [8 over which it cascades.

In practice the surface l8 may be fiat. slightly 1!], .the bearing '24 is supported on a carriage 46 operating in a track 48. A lever 50 hinged on a concaved or convexed or any other form tending to spread the contracted stream of molten metal out into a ribbon of uniform shape.

While the present invention has been primarily designed to be used in the making of peening, cleaning and abrasive shot of white cast iron, it will be understood that it is equally as applicable to other molten metals for forming spherical bodies through atomization and quenching.

One of "the outstanding advantages of the method herein disclosed resides in the economical use of fluid pressure. For example, using the present method, steam pressure may be reduced in the.- order of 60% or more with 2. corresponding reduction in volume, as compared with standard methods now in use.

Having thus described my invention, what I claim as new and desire to cover by Letters Patent is: s

l. The method of improving uniformity of size in the manufacture of solid substantially spherical metallic shot comprising the steps of drawing molten metal from a source subject to surges due to irregular production and feeding, pouring the molten metal in a contracted stream onto the upper portion of an angularly inclined surface to spread and flow and even and smooth out in a thin ribbon of substantially uniform thickness at all points throughout its width as the ribbon pours and cascades over the lower edge of the inclined spreading surface, supplying fluid under jet pressure substantially at right angles outwardly through the cascading ribbon of molten metal -substantially uniformly throughout the width of the ribbon, and adjusting the angularity of the inclined surface to vary the width and depth of the ribbon-like stream of .molten metal as it cascades whereby the size of resultant shot can be controlled and varied to suit different conditions of use. v

2. A method of improving uniformity of size in the manufacture of relatively solid sphericallike metallic shot and grit comprising the steps of drawing molten metal from a source subject to surges dueto irregular production and .feeding, in a gravity flowing and a surface tension contracted stream, directing the contracted stream upon a flat surface disposed at an abrupt angle in said stream to. even out the surges and to spread the contracted stream by gravity into a ribbon-like stream over the edge of which the thin ribbon-like stream cascades, subjecting the ribbon-like stream to fluid pressure, to break the same into globules of .relatively uniform size and 'then quenching the globules to form relatively solid spherical bodies, and regulating the relative angularity of said surface to increase or' decrease the size of the metallic shot and grit being formed.

IDAR OLSEN.

REFERENCES CITED The following references are of record in the file of this patent: r

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